Where can i buy game for Yuzu and citra?

Where can i buy game for yuzu and citra? because I don’t support piracy

Amazon, second hand marketplaces like Ebay or the Nintendo e-shop. After that, you can dump the games for use in emulation using our dumping guides:

For Yuzu:
Quickstart Guide - yuzu

For Citra:
Dumping Game Cartridges
Dumping Installed Titles
Dumping Updates and DLC